为什么我的班级表现得像静态班？

Question

我有一个模块(实际上是单个.py文件),有一个名为HashedDir的类.

当我导入文件并实例化该类的2个实例时,当我检查对象的字段时,它们总是相同的,即使这两个对象应该是不同的.

例如:

 h1 = HashedDir('/path/to/dir')
 print h1.getList()['files'] # /path/to/dir
 h2 = HashedDir('some/other/path')
 print h1.getList()['files'] # some/other/path
 print h2.getList()['files'] # some/other/path

任何的想法？

这是班级:

from os  import walk
from os import path
from hashlib import md5
import re

class HashedDir:
    """
    A list of files with associated md5 hashes generated retrieving thou
    a recursive walk in the directory tree starting from a provided root
    directory. Also stores the dirs in each dir
    """

    #  {'files': [
    #    ('/path/to/file1', '52bc309e11259af15e4623c7a0abc28c'),
    #    ('/path/to/file2', '52bc309e11259af15e4623c7a0abc28c'),
    #    ('/path/to/dir/file3', '52bc309e11259af15e4623c7a0abc28c')
    #   ],
    #   'dirs': ['/path/to/dir1', '/path/to/dir2']
    #  }
    fileList = {'files': [], 'dirs': []}
    ignoreList = []

    def __init__(self, rootDir, ignoreList=[]):
        """
        ignoreList is a list of regular expressions. If a file or a dir matches
        that regular expression, don't count it
        """
        self.ignoreList = ignoreList

        for dirpath, dirnames, filenames in walk(rootDir):
            for fileName in filenames:
                completeName = path.join(dirpath,fileName)
                hash = md5(open(completeName).read()).hexdigest()
                relativePath = self._relativePath(completeName, rootDir)
                if not self._toBeIgnored(relativePath):
                    self.fileList['files'].append((relativePath, hash))
            for dirName in dirnames:
                completeName = path.join(dirpath, dirName)
                relativePath = self._relativePath(completeName, rootDir)
                if not self._toBeIgnored(relativePath):
                    self.fileList['dirs'].append(relativePath)

    def _relativePath(self, path, base):
        return path.replace(base, '')

    def _toBeIgnored(self, path):
        for regex in self.ignoreList:
            if re.compile(regex).search(path) != None:
                return True
        return False

    def getList(self):
        return self.fileList

提前致谢

Answer 1

类中有两种变量:

• 类变量,在类级别定义,并且对所有实例都是通用的

• 实例变量,一个类的方法(通常是内定义__init__)和合格的由实例(通常self.).

例

class SomeClass( object ):
    classVariable = 0
    def __init__( self ):
        self.instanceVariable= 0

名为的变量classVariable是类的一部分,对所有实例都是通用的.由于的方式Python做搜索,它可以作为成员self.classVariable,以及SomeClass.classVariable.

名为variable的变量instanceVariable是instance(self.)的一部分,并且对每个实例都是唯一的.

注意.还有第三种,全球性的,但这不是你所要求的.

Answer 2

你在谈论文件列表吗？您将它作为类变量,使其成为您需要执行的实例变量:

self.fileList = {'files': [], 'dirs': []}

在你__ init __函数中.